[musa]

Embarrasing dark/whitish oily smoke when coming to a stop is now gone! Taken me 2 years to finally get the work done. Did it right in my garage under jack stands. Took me about 2 weeks:
1) Pull out RB turbos and sent them to Rob for a rebuild ($850). Looks like new with new and rebuilt components
2) Changed valve covers
3) Oil pan gaskets changed
4) Drain/refill trans and diff

Rob verified turbo seals not leaking. I believe the new valve cover fixed the smoke issue. Man, it's a great feeling and sight to be smoke free! Thanks to all the DIY I followed involving completely removing the subframe.

All the work I did was not really tough but time consuming and requiring extreme care, especially when installing the turbo lines to avoid leaks. I'm just a slow DIY and a software developer, so anyone can do this.

[madmantwo]

Nice! I am about to start this journey myself, getting clouds of smoke when coming to a stop. I replaced the valve cover and gasket a while back, so I don't think that's the problem...probably turbos.

I am also a software developer in the Seattle area and DIY everything I can, might hit you up for pointers when I inevitably replace my turbos

[mike@x-ph.com]

Glad you are good now

[musa]

Oh, I forgot - and how dare I ..... also did at the same time a complete suspension overhaul with ST XTA coilovers and new parts except the subframe bushings for which I have no tools to tackle. The subframe bushings are sitting in my garage. Car drives amazing and with no smoke to ruin the fun!

[musa]

Originally Posted by madmantwo

Nice! I am about to start this journey myself, getting clouds of smoke when coming to a stop. I replaced the valve cover and gasket a while back, so I don't think that's the problem...probably turbos.

I am also a software developer in the Seattle area and DIY everything I can, might hit you up for pointers when I inevitably replace my turbos

No problem. I actually wrote a summary of pointers gleaned from most of the DIY posts and comments. I would quickly scan the list as I lay under the car in my garage to make sure I didn't forget a crucial step! My wife thought I was finally going cuck-oo, LOL! It was time consuming going through each DIY post to glean pointers. I put all pointers on one page and will share out.

[madmantwo]

Originally Posted by musa

No problem. I actually wrote a summary of pointers gleaned from most of the DIY posts and comments. I would quickly scan the list as I lay under the car in my garage to make sure I didn't forget a crucial step! My wife thought I was finally going cuck-oo, LOL! It was time consuming going through each DIY post to glean pointers. I put all pointers on one page and will share out.

Oh that's a really good idea, I'd love to see that list of pointers. I'm actually about to do my subframe bushings this weekend, rented the tool from HPA if you want to borrow it when I'm done

[Jeff@TopGearSolutions]

Lots of guys with valve covers cracked and they have no idea. That's the first step for any "smokers".

Glad you got it sorted.

[BMWhoarder]

its a shame you did it all at the same time. It would have been interesting to see if simply the turbo rebuild corrected it.... despite rob saying they were fine, i have feeling they were the likely reason behind the smoke.

[mikeseli]

Did each turbo have its own dedicated exhaust pipe? Did both exhaust pipe smoke or just one? If only one smoked than that turbo is the cause.

If both tail pipes smoked than it could be the valve cover or it can also be both turbos.

[musa]

One tail pipe smoked more than the other. So here's my turbos notes borrowed in a nutshell form from threads below:

Great DIY with great pics! Used it to do my turbo replacement...
http://www.e90post.com/forums/showthread.php?t=1087276

Also a good one with pics!
http://www.n54tech.com/forums/showthread.php?t=17812

Turbo notes:

-The power steering hose should be unbolted from the steering rack at the U-bend before swinging the rack out of the way; Rubber isolation mount could break in half (probably due to becoming brittle after many years) after twisting the rack towards the driver's side. Dealer does not sell a replacement.
-Instead of unbolting the coolant hose running along the front of the subframe, you could just undo the quick disconnect at the driver's side frame-rail (which goes to the heater)... IF you manage to separate the connection as there are no leverage points to assist. These BMW coolant disconnects can be difficult to separate after all these years, but if you're lucky, it will save a ton of time trying to squeeze your hand and using itty bitty turns to remove and replace that pesky screw below the power steering pump as you would keep that coolant hose completely attached to the frame. The alternative is to wait until you can partially drop the subframe in order to gain more clearance to remove the screws.
-Can be challenging to disconnect the lines on the turbos. Use a screw driver and try to wiggle the line as you pull it off, but be very patient so that you don't end up bending the flange!
- Vacuum out any debri from the block
- Use new studs
- Here is bolt pattern used to get manifold on evenly
7-2-3-5
6-1-4-8
- Do NOT go crazy on the bolts on the coolant/oil feed lines...they do not need much force.
- Do not over-tighten or force sockets on the coolant line fastening nut, stripping the preinstalled stud may occur. Use a 10mm wrench and tighten lightly.
Torque specs:
Bracket to cylinder head: 9Nm
Coolant supply line to crankcase: 9Nm
Coolant return line to crankcase: 8Nm
Coolant return line to turbo: 8Nm
Coolant supply line to supply line: 8Nm
Exhaust manifold heat shield: 8Nm
Oil supply line to crankcase: 20Nm
Oil pressure line to turbo: 8Nm
Oil return line to crankcase: 8Nm
Oil return line to turbo: 8Nm
Turbo manifold to head: 20Nm
- Its much easier to put both drains on the turbos on the bench. They install easily in the block as you are putting turbos in. This will help eliminate leaks and make life easier than fighting it in the car.
- For RBTurbos, use the provided custom coolant line spacers on each turbos' lower coolant line. The top coolant line installs first, then the lower last with spacer.
- install the turbos with the majority of the lines attached
- install upper coolant lines to the engine block before installing front and rear turbos
- Install rear turbo first then followed by front turbo
- install heatshields after you install the turbos but start to put them on and tighten their bolts BEFORE tightening manifold.
- Do not connect the junctioned lines and tab and front turbo heat shield before both rear and front turbo are installed.
- lube all o-rings first!!
- First plug into the engine block the junction fitting. install and tighten the hold down bolt to the block.
- Do not install front turbo junctioned oil supply line to the turbo. Install it to the junctioned fitting first and then mount the front turbo and heat shield, and then attach the other end of the oil supply line to the turbo. There is enough room to put in the hold-down bolt and tighten it with a small torx bit wrench.
- While rear turbo is loose connect the junctioned lines together (Once bolted there is no play in the line)
- For the rear turbo pre-install the oil supply hose to the rear turbo first because there just isn't enough room to install the hold down bolt by hand.
- Top coolant lines can not be fully installed until turbo is installed fully. Put coolant line end lined up with holes (top right corner on front turbo and top left of rear) and when turbo is bolted down it will push line in).
- The big turbo oil lines with metal gasket can be very tight, basically hard to hold in place with gasket while lining up holes, bolt in one side with the gasket on....then slide gasket over and tighten the other side.
- Do not tighten clamp fully ... pipe has to rotate so that the other side of tube can line up with the rear turbo. If clamp is tightened in the wrong spot the pipe will not reach rear turbo.
- Before installing the front turbo loosen induction tube bolts for more clearance.
- After front turbo is installed connect vaccum line to actuator, if you wait you will be sorry!
- Make sure induction tube is flush on turbo.
- Do not forget to put wastegate vacuum lines on before installing induction tube, lines etc.
- Double-check all your hoses and clamps to make sure they are on correctly.
- NEVER put the turbo induction gasket on the turbo...install it in the tube first! This could cause the induction tube not to fit. Do not install the gasket on the turbo first otherwise the induction tube will pinch the gasket and deform it and tube would not be put on.
- For the downpipes to line them up put some grease on the seals so they stay stuck on the pipe and not moving and getting on the way. Then loosen the nut holding the DP and use a plier to press them together.
- Undiluted coolant is a great lubricant when reconnecting hoses especially if you're using new ones
- Finnish everything and add oil and coolant, purge the system
- To prime turbos after install, disconnect the injector power lines for each injector. Crank engine over for 60 seconds to prime the turbo (let the oil flow through the thrust bearings) before turning on the engine. Reconnect them.